The present invention relates generally to improved methods for heating ski boots so as to permit drying of wet boots, warming of cold boots, and/or softening of the molded foam interiors of such boots so as to improve the comfort thereof when such boots are donned; and, more particularly, to improved methods for heating ski boots while such boots are firmly, yet removably, clamped with their flat soles in surface-to-surface contact with a relatively flat surface so as to prevent warpage of the ski boot during the heating and/or drying process. In a preferred embodiment, the present invention relates to improved methods for clamping such ski boots to a vertical surface with the soles of the boots vertically oriented--such, for example, as the orientation inherent when such boots are mounted in a boot and shoe tree of the type disclosed in I. J. Allsop U.S. Pat. No. 3,210,787 assigned to the assignee of the present invention--and for externally and conductively heating at least the lowermost portions of the vertically oriented flat soles of the boots so as to generate convective air currents within the interior portions of the ski boots which serve to convectively heat substantially the entire inner surfaces of the ski boots.
In recent years there has been a tremendous increase in public interest in participative athletic events such, for example, as skiing. Such increased interest has been reflected in an ever increasing number of people who desire to participate in a wide range of skiing activities such, merely by way of example, as downhill skiing, cross country skiing, and ski jumping. These various activities are commonly carried on on both a competitive and a non-competitive basis, as well as on a professional and amateur basis.
Along with the increased interest and participation in such activities has come a rising awareness and concern by both the public and the manufacturers of skiing equipment, as well as by the operators of skiing facilities, of the physical dangers inherent in virtually all types of skiing activities. Consequently, manufacturers have significantly upgraded the quality of ski equipment, with particular attention having been directed to automatic release bindings and improved ski boots, in an effort (i) to minimize the danger of injury resulting from accidental falls and the like, and (ii) to maintain rising interest levels in participative skiing activities. As a result of these efforts, today ski boots tend to be rather sophisticated products made of high-quality materials and designed to both minimize the risk of physical injury and to improve the comfort and the wearability of such boots. This, of course, has resulted in the manufacture of ski boots which represent a relatively significant investment on the part of the purchaser, with such boots commonly ranging from sixty dollars ($60.00) to one hundred and fifty dollars ($150.00) per pair and, often, considerably higher.
As the standard of living has increased, more and more skiing facilities have been opened and, consequently, an ever increasing number of people have had both the economic means and the opportunity to participate in skiing activities. Such individuals have tended to demand that ski equipment purchased be of high quality and employ the latest safety and comfort features available. Thus, today it is common to find that most skiers--whether amateur or professional, and whether beginner, intermediate or skilled--own or rent high-quality ski equipment; particularly high-quality ski boots and bindings. Such ski boots represent a significant investment for both the individual owner and for the operator of ski facilities who is engaged, inter alia, in the rental of ski boots. Because of this investment, it is important that suitable provisions be made for insuring that the ski boots are maintained in the best possible condition at all times so as to (i) increase the expected life of this quality product, and (ii) to insure that the ski boot remains in peak condition compatible with the design criteria for boot and binding combinations which is necessary to meet high safety standards.
Inherently, the very nature of skiing activities results in subjecting ski equipment--particularly ski boots--to a wide range of environmental changes in terms of both temperature and moisture content resulting from melting snow and/or foot perspiration within the boot. Therefore, failure to exercise care in the maintenance and preservation of such boots can significantly shorten boot life and can also deleteriously affect the desired safety features of the boot. Consequently, it is important the owner of such boots take appropriate steps to both store ski boots and to dry wet boots and/or warm cold boots under controlled conditions which insure that the boots are not subjected to warpage--an undesirable condition that not only affects the safety factor when attempting to use a warped boot in a specially designed, quality, quick-release ski binding, but, moreover, also results in damage to the boot uppers and to the molded foam boot interiors, thereby affecting both the wearer's comfort and the life expectancy of the boot. And, of course, it will be appreciated that the wearer's comfort is, in and of itself, an important safety consideration since skiers who are not properly outfitted in comfortable ski boots are more likely to be prone to accident than those who are comfortably and properly outfitted.
With the foregoing considerations in mind, numerous efforts have been made to design ski equipment which will enhance both the life expectancy of ski boots and the safety features that are designed therein. Today, a large proportion of the owners of relatively expensive ski boots also own suitable boot and shoe trees which serve to maintain the ski boots in a fixed, desired condition of flexure during periods of nonuse. For example, most ski boots today are designed with relatively thick flat soles, and with relatively thin uppers often surrounding a foamed thermoplastic inner which is commonly molded to conform to the shape of the wearer's foot. It is, therefore, important that the ski boot be maintained in this state, particularly during periods of nonuse and/or storage when warpage can result as conditions of temperature and moisture content change. Thus, most commercially available boot and shoe trees are designed so that the flat bottom surfaces of the boot soles are firmly, yet removably, clamped in a flat planar condition during periods of nonuse and/or storage, thereby insuring that the boot does not warp as temperature and moisture conditions change. Typical of such boot and shoe trees is that disclosed in the aforesaid I. J. Allsop U.S. Pat. No. 3,210,787 which is commonly sold under the trademark BOOT-IN.RTM., a registered trademark of Allsop Automatic, Inc., of Bellingham, Washington.
Moreover, since skiers will commonly wish to remove their ski boots for short periods of time--for example, between separate morning, afternoon and/or evening skiing activities, or overnight--it is important that suitable provisions be made available for heating such boots during short periods of nonuse so as to quickly dry wet boots, warm cold boots, and/or warm the molded thermoplastic interiors of such boots so as to soften the foam interiors and thereby increase the comfort characteristics of the boots when the boots are again donned. Many types of heating equipment have been designed over the years in an effort to meet this need both in connection with conventional shoes and/or boots and, in some instances, specifically in connection with ski boots. One early drier system suitable for use with conventional shoes and boots is described in Lund U.S. Pat. No. 1,318,780 where the boot is simply placed on a heated platform which may be either flat or shaped to conform to the normal curvature of the boot or shoe sole. In either case, no provision is made for preventing warpage of the boot or shoe and, consequently, the very drying process tends to promote warpage.
Additionally, numerous types of devices have been developed for insertion into the boot or shoe for promoting drying thereof. Typical devices include those described in Doyle U.S. Pat. No. 1,543,828, Lessard U.S. Pat. No. 1,733,611, Yentis U.S. Pat. No. 2,098,735, Bosse U.S. Pat. No. 3,632,963, and Riley U.S. Pat. No. 3,867,611. Again, the flexible nature of the devices described in these patents is such that the drying process tends to promote warpage of the boot or shoe.
More recently, a ski boot and glove warmer has been disclosed in Lee U.S. Pat. No. 4,145,602 wherein a coin operated apparatus is provided for blowing hot air into the interior foot area of the boot for a predetermined period of time. Again, the arrangement is such that the very drying process employed tends to promote warpage of the ski boot.